The types of cells can be classified into two main types, and these are chemical cells and physical cells. Chemical cells can be further classified into three types such as primary cell, secondary cell and fuel cell, whereby the main characteristics of a fuel cell are that a fuel cell has a positive electrode as well as a negative electrode, and active substances are not present in the fuel cell. In addition, active materials need to be supplied externally and continuously to the fuel cell, so as to enable the fuel cell to be discharged continuously. As such, in order to produce electricity continuously, the positive electrode (the cathode) of the fuel cell need to carry out an oxidation reaction with oxygen from the external air.
Among all of the cell types of fuel cells, nowadays the zinc air cell may provide a high energy density on the basis of all of the electrolyte-based cells. Besides being reliable and safe, the other advantages of zinc air cells include having low costs of manufacture, being easily recycled, and having low pollution rates.
FIG. 1 shows the structure of a conventional zinc air cell 1. The conventional zinc air cell 1 may be mainly made up of a zinc anode plate 10 and a cathode plate 11. The zinc anode 10 may perform the function of the negative electrode (anode), and at the same time may perform the function of a fuel cell of the zinc air cell 1. In the conventional zinc air cell 1, the oxygen from the external air 12 may act as the depolarizing agent of the hydrogen atoms. The external air 12 may diffuse and enter the structure of the conventional zinc air cell 1 via the side of the cathode plate 11, to enable the zinc anode plate 10 to have a chemical reaction with oxygen from the external air and thus produces electricity.
However, since the external air only contains 21% of oxygen, as such, if the generation of electricity is only by means of chemical changes, the power supply efficiency of the conventional zinc air cell 1 would be very limited. Further, electricity generation by means of chemical changes cannot be used for a long time, to gradually increase the power supply efficiency of the conventional zinc air cell 1.
In view of the above, there are still limitations on the practical uses of the conventional zinc air cell 1, and that there is still a need to have an improvement on the conventional zinc air cell 1. The improvement of the conventional zinc air cell may be achieved by the creation of a type of zinc air cell that may be used in the long term, so as to gradually increase the power supply efficiency of the circulatory system for the zinc air cell.